Tuning-fork



J. C. JINKINS. `TUNING PORK.

No. 11,566. Patented Aug. 22. 1854.

IIE'

UNITED STATES PATENT OFFICE.

JOSEPH C. JINKINS, OF BEALLSVILLE, OHIO.

TUNING-FORK.

Speceation of Letters Patent No. 11,566, dated August 22, 1854.

To @ZZ whom may concern:

Be it known that I, JOSEPH O. JINKINS, of Beallsville, in the county ofMonroe and State of Ohio, have invented a new and Improved Tuning-Fork;and I do hereby declare thatthe following is a full and exactdescription thereof, reference being had tO the accompanying drawings,making part of this specification.

The nature of my invention consists in producing sounds Of any requiredpitch, by means Of a movable cross-bar inserted in the proper positionsbetween the prongs of the fork, substantially as hereinafter set forth.

In the accompanying drawings, Figure 1, represents a tuning fork ofordinary construction, without the movable cross-bar; Figs. 2, and 3,different views of the crossbar; and Fig. 4, view of the fork, with thecross-bar inserted for use. Like letters designate corresponding partsin the several figures.

The manner of constructing the fork itself does not essentially diiferfrom that ordinarily followed; except that, in general, it is madelarger,especially when intended for tuning piano-fortes and otherinstruments requiring the tones of several Octaves. The cross-bar a, issimply a stiff metallic rod, lor piece, of suitable length to littightly between the prongs of the fork, as shown in Fig. 4; and in orderthat it may be made to press with sufficient force between said prongs,I usually cause them to spring inward a little toward each other, whenthe cross-bar is removed, as seen in Fig. 1, so that they will requiretovbe separated somewhat to insert Or adjust the cross-bar, and willthen automatically retain the same. It

is best to have the ends of the cross-bar pointed, as represented in thedrawings, for the purpose of more readily adjusting it in the exactposition required, to produce a given sound. A thumb-piece I), may alsobe added to it, for convenience in handling. The manner Of tightening itin the fork by the spring of the prongs, I have described as aconvenient means of attaining the end; but a tightening screw, or otherequivalent devices, may be substituted, if desired.

It is obvious that, by varying the positions of the cross-bar betweenthe prongs of the fork, any number Of different tones vmay be produced.In order to render the instrument more accurate and useful, I alsogenerally mark the positions of the different tones and semitoneswithin'the compass of it, upon one of the prongs of the fork, anddesignate them by the appropriate letters, as shown in the drawings. InFig. 4, the cross-bar is represented as inserted at C, in the lirstoctave; and if the scale is nicely determined by the maker, the soundindicated thereby will invariably be given.

Vhat I claim as my invention and desire to secure byLetters Patent, is

Producing sounds of any required pitch, with a single tuning fork, bymeans of a movable cross-bar inserted in the proper p0 sitions betweenthe prongs Of the fork, substantially in the manner herein set forth.

' The above specification Of my new and improved tuning fork signed byme this sixth day of July 1854.

JOSEPH O. J INKINS.

Witnesses:

J. S. BROWN, AARON W. GEAI-IEART.

